Control switch particularly for electric sadirons and similar devices



L. REICHOLD Sept. 8, 1931.

CONTROL SWITCH PARTICULARLY FOR ELECTRIC SADIRONS AND SIMILAR DEVICES Filed Dec. 23, 1929 2 Sheets-Sheet l QN E Q S Q ww Q S Sept. 8, 1931. L. REICHQLD 1,822,315

CONTROL SWITCH PARTICULARLY FOR ELECTRIC lsADIRONs AND SIMILAR DEVICES Filed Deo. 25. 1929 2 Sheets-Sheet 2 gru/vento@ UNITED .STATE Patente/d Sept. 8, y1931 FICE LUDWIG- REICHOLD, OF WINSTED, CONNECTCUTV, ASSGNGR T FITZGERALD MANUFACTURING COMPANY, 0F TORBENG'TON', CONNECTCUT, A CORPGRATION 0F ooNNEoTIcUr l(N'.lllEtOl'i SWITCH.' PARTICULRLY FOR ELEGTRIIIC SADRONS AND SEMILAR DEVCES .Application tiled December 23. 1929. Serial No. 4l6,l26.

'lhis invention relates to improvements in thermostatically controlled switches and is more particularly intended for employment on electric sad-irons or similar devices in which it is desired to maintain the device at a substantially constant temperature,

' with the possibility ot varying this tempera ture to a higher or lower degree.

@ne ot the particular features of this invention is the provision ota switch which isv quickly made or broken at a predetermined va'riajoleV point, the contacts being so actuated that they are fixed in the inades or broken positions and move between these positions rapidly and without delay.

Another feature otqthe invention is tok construct a switch oihthis type with the eniploynient of a double toggle system, these toggles being subjected to strong and wealr spring edects7 whereby vone toggle system causes the switch contacts to remain in either made or broken39 position.i while the other toggle causes the rapid shitting oi the contacts between made and broken positions.

A further feature of the invention is the provision of a structure in which the spring edects are maintained at definte ratios9 so that one toggle" is subjected to a strong spring eect and the other to a weak spring effect: and more particularly to establish these ratios at delinite values by the ernployment of lever arms.

Still another feature of this invention is to obtain these spring e'ects upon both toggles by the employmentv of single spring, and more particularly to .so construct and arrange the mechanisms'that this spring is, maintained in a position in which it is substantially, protected from heating by the device, whereby its-temper and springiness are preserved.

Still a further teatuxv'e of the invention is the provision of a peculiar type of thermostatic bar control for the switch elements, whereby the thermostatically produced movement is regulated and adjusted as dej sired by the operator of the iron, so that the temperature is maintained in the device.

With these and other objects in view, as y will appear in the course of the following specification and claims, the switch and associated parts will now be described in an illustrative `form in connection with a sadiron, but it will be understood that this is by way of illustration andinot of limitation as to the application oi the invention and its several features in the arts. f

ln these drawings:

Figure l is a longitudinal sectional view substantially on line rel of Fig. 2.

Fig. 2 is a corresponding horizontal view `with handle removed and the cover or skirt broken away, and with other parts in dotted lines to indicate their relative positions.

lEig. 3 is a diagrammatic view showing the relationship oi" the moving parts, with the switch plate omitted for greater clear-` ness.

lllig. is a similar view of the thermostatic plate and control members.

llig. 5 is a transverse sectional view substantially on line 5 5 of lig. 2.

Fig. tl is a'perspective view showing in detail the construction of the cam control shaft. i

llfig. l is a similar detailed view ci a lever control arm.

According to the present invention9 aj thermostatic switch is provided with a there mostatically actuated member which controls the position of a iirst toggle linkage, this toggle linkage being' free to move with re spect to a second toggle linkage between defi-- nite limiting positions. At 'these limiting positions, the r'irst toggle linkage causes a movement of the second toggle linkage between deinite end positions: so that circuit closing 'elements connected to the second toggle linkage are heldor moved rapidly perspective and positively between open and closed position by the action of the second toggle linki age, while the first toggle linkage serves as switch 1s provided with a regulatable point 00 By controlling the point at which of cut-oli? or make-andbreak, so that the temperature of the entire devlce 1s closely and definitely regulated: and in a particular illustration, this is effected by a direct l"control of the thermostatic element itself.

In the drawings, the invention has been illustrated as applied to an electric' iron having the base or shoe member 10 which supports the heating element 11 directly in l smooth external surface for the entire iron.

The handle strap 17 rests uponffdished washers 18 supported upon the skirt 16'and is provided with a handle of any desired shape (not shown). Stud screws having the polygonal section 19 by lwhich, the lower threadedl ends 20 may be screwed into the shoe 10,.serve to clamp'the clamping block 12, the heating element 11 and the shoe 10 tightly together. The upper end of each of these screws 19 is assed through a correspondinglaperture 1n the skirt, through the respective washer 18 and a hole in the handle strap 17, and receives a cap 21 which serves in 4turn to clamp the handle and wash# er 18 tightly down upon the skirt 16, so that in effect the screws 1 9 serve to clampk all parts of the iron rigidly together: and conversely, by separating and removing these screws, the several parts may berrenioved one from another for inspection and repair of the iron. The plug protecting sleeve 22 has a rearwardlyv bent curl 23 which acts in conjunction with the heel guard 24 lto form a support for the iron when turned. over to rest on these members, the shoe 10 then being out of contact with the ironing board or material of the iron,

and this position constituting an easy and immedlately available rest for the iron when hot. It will particularly be noted that the` heel guard 24 is supported from the apron or skirt 16 and is of sheet metal with a space between its upper and lower members, the

lower member having an aperture 25 formed therein for Ventilating and maintaining this heel guard cool.` i

The clamping block 12 receives a switch plate 26 which is secured thereto by screws 27. u Beneathy this plate Vand within the cavity 13 1s provided a thermostat bar 28 which may be ofthe usual bi-metallic or other type and is' secured by a screw 29 to L.the clamp1ngblock12 The free end of the The electric circuit of the illustrated iron extends from one plug prong 32 which is supportedon an insulating bridge 33 by a band conductor 34 to one terminal of the heating element 11, with a return by a lsimilar band conductor 35 from the other end of the heating element to a switch terminal plate'36 which is securely riveted to, but insulated from, the switch plate 26. A-similar switch terminal plate 37 is riveted to, but likewise insulated from, this switch plate 26; and in turn is connected by a conductor 38 to the other prong 39 of the insulating bridge 33. Each of the switch terminal plates 3 6, 37 is provided with an upturned y end 40 (Fig. 1) having a contact 41, 42 thereon to engage with the similar contacts 43, 44 carried by a floating bridge member 45 but insulated therefrom, the individual contact points 43,44 being connected by a conductive web 46 (Fig.'3). n

The switch (plate 26 has a slot 47 therein to receive a slider 48 which has a long 'foot 49 to prevent it from being pulled upward through the slot47, and for guiding it for movement back and forth in this slot. The upper portion of theslider 48 has two apertures 50 and 51 therein. e plate likewise has two upstanding studs 52', 53 therein, each vof which has a V-shaped The switch i 7sA y notch for the reception of the sharp yends Y of respective toggle members 54, 55, which extend through the respective apertures 50, 51l of the slider 48- and have V-shaped grooves in their free endsto receive lthe ends of the second toggle link members 56, 57, which are formed of thinner material and have narrower ends suchas 58 (Fig. 5) to rest' within the channel-shaped pressure arms 59, 60, while the shoulders'presented by the res ective members 54,I 55V bear against Y-s aped notches 61 provided in these members. lIt willbe noted that the effective width of the aperture 5() is less than res onding Wall of its aperture 51 when the sli er 48 is in one position, until the toggle linkage 55, 56- has slightly passed its position of dead center, and isutherefore capable l of immediately snapping to its other end pothe effective width of the aperture 51: and i sition, and therewith carryigthe slider 48 along. The slider 48 has an extending end 62 which passes through an aperture of the bridge 45 and has clenched claws to hold the rocking bridge 45 in position, while permitting it to 'rock laterally4 slightly in all diinto the notch 31-of the end plate 30 of rthe thermostatic bar 28, being somewhat thinner than the size of this apertiire, so that as the end ^plate 30 forces the spur 63 in one direction and thereby also the first toggle linkage 55, 56, it causes this first linkage to come into contact with the slider 48 and thereby move it in one direction, the spur 63 being per- 'mitted a slight free movement in this slot of sufficient degree soI that the bridge 45, and contactpoints 43, 44 will quickly and positively make or break the electrical circuit.

rlhe lever arms 59, 60 are pivotall mounted on. studs 64, 65 upstanding rom the switch plate 26: it being preferred to provide sleeves 66 about'the posts and to secure these sleeves in position by `tet screws 67 whereby to support the lever arms 59, 60`

away from the switch plate 26. Extensions 68, 69 are secured to the lever' arms 59,60 as by welding and have their rearward ends bent inwardly and then .outwardly to provide the end ieces '(0, 71 with apertures therein to receive the outturned ends of the coil spring 72 which is located wholly withv in the clamping block 12. The upper end lte of this shaft is provided with a portion 83 `Vof irregular section to receive a handle84 with a knob 85 therein. The yupper end ci the shaft 81 has screw threads 83a to receive a cap 84a which holds the handle 84 rigidly to the shaft. As the shaft is rocked, the cam bears more or less against-the thermostatic bar (compare Figs. 3 and 4) so that a given bending ot the bar in consequence ot its heating will produce a lesser or greater movement of the end plate 30 thereof.` For example, in Fig. 3, the pressure of the cam 80 against the thermostatic bar is practically eliminated at its cold9` position, so that the bar swings substantially from its securing screw 29 and therefore the plate 3() makes a considerable movement, and soon operates the spur 63 to cause a shifting of the switch and thereby yan opening of the circuit: and,

in other words, therironis open-circuited aty a` relatively low temperature. llt will be noted that the position of the handle 84 and knob 85 of Fig. 3 corresponds to the lit is preferred` the cam 8O bears more against the thermostatic bar 28, as in l? ig. 4, the bar will causey a lesser movement of the end plate 30 for a given temperature, and hence a greater temperature will be necessary to move the spur 63 sufficiently to cause a snapping movement of the first toggle linkage 55, 56 and thereby provoke an opening of the circuit; in other words, the iron will operate at a higher temperature, and the handle 84 must have been moved for this purpose in a clockwise direction about the axis of the shaft 81, i. e., further toward `the position shown bythe dotted letters HGH in l? ig. 2.

lt will particularly be noted that the lever arm from the pivot 64 to the l-notches 61 of the lever arm 59, is less than the corresponding arm from the pivot 65 to the notches 61 of the-lever arm 60: and on the contrary the lever arm from the pivot 64 to the engaging point at the end of the extended arm is greater than the corresponding distance from the pivot 65 to the engaging portion of the corresponding end 71: so that by the employment of a single spring 72, a much greater endwise springy compression is exerted upon the first toggle linkage 55, 56 than upon the second toggle linkage 54, 57. ln other words, the snapping efliect of the first toggle linkage 55, 56

is accomplished with much greater energy than that of the second toggle linkage 54, 57, and this effect is wholly independent of the actual force exerted by the single spring 72, and is a consequence of the lever ratios of the two systems. l

ln operation, the current having been turned on the device, the heating element 11 causes the several parts to rise in temperature until the thermostatic bar 28 moves through a definite arc, the temperature at which this arc is completed being determined by the prevailing position of the cam `as regulated by the shaft 81 and handle 84 and as maintained by the spring pressure plate 86 which is clampedbetween the handle strap 17 and one of the washers 18, and

has a downward bow tofexert a frictional pressure on the handle 84 and thus to hold this handle in the set position.

lt will be understood that while the iron is cold the parts are in the position of lFig. 2. lVhen the plate 30 moves through this arc angle, at rst the plate moves until the width of the notch 31Vis takenv up, and thereafter the end plate 30 acts upon the spur 63 to rock the corresponding toggle linkage 55, 56 so that the joint between the two ntoggle elements moves relatively toward the left, but for the moment without contact with the" slider 48, in consequence of the .l lli width of the aperture l51. The relative 5 contact with the slider 48, the toggle linkage ,has passed its position of dead center; and no longer exerts an outward force against the leverarm 5.9, and thereby against the spring '72: but now the spring delivers its energy through this lever arm 59 and causes the first toggle linkage 55, 56 to rapidly snap and move its center joint vtoward the left, carrying the slider 48 therewith and thus dragging the contacts 41, 43 and 42, 44 apart and breaking the circuit. During the time that the first toggle linkage 55, 56 has been moving independently of the sliderN 48, this slider has been held in closed position as shown in Fig. 2, by the action of the second toggle linkage 54, 57 which, however, is subjected to a much smaller endwise spring compression by reason of the differing lever ratios of the arms 59, 68 with respect to the arms 60, 69: the snapping movement of the first toggle links 55, 56 is therefore sufficient-to rapidly and immediately drag the Acontacts apart, thus securing a proper opening of the circuit to the iron. The parts are then in the position shown in Fig.,3, the lever arms 59, 60 having moved from approximately the full `line position to thatshown-in dotted lir'ies and back againv Lduring the course of the operation just described, while the thermostatic bar has moved from the dotted line position to the full line position.

As the iron cools off, the thermostatic bar 28- moves 4from the position shown in full lines to that shown in dotted lines. in Fig. 3, at first freely by reason of the notch 31,

and then engages the' spur 63 and moves,

the first toggle linkage 55, 56so that its connecting Joint travels ,toward the right in Fig. 3, againkmoving freely for the first part of itsmovement by reason of the Width ofI the aperture 51. The second toggle linkage 54, 57 meanwhile holds the slider 48 against movement and keeps the circuit open at the lcontacts 41, 43 and 42, 44. Just at or after the time that the first toggle-linkage 55, 56 comes to dead center, the elements of this toggle'linkage come into contact with the y slider 48, and cause this slider to be snapped quickly and immediately toward the right, thus quickly closing the circuit anditlie contacts. For the reasons above stated, the endwlse compression of the second toggle linkage 54, 57 is less than the endwise com` pression of the first toggle linkage 55, 56, and therefore the first toggle linkage entirely controls the opening and closing movement, while the second toggle linkage 54, holds the .parts either in open or in closed position. i

' In order to prevent sticking or binding of the parts if any rusting or corrosion should occur in the device, the apertures 50, 51 are preferably formed ofgreater width than is necessary, and the walls are provided with spurs 90: and the studs 52, are provided with base flanges 91 to support the toggle linkage 54, away from the switch plate 26, thus acting in conjunction with the supporting effects of the lever arms 59, 60 upon the toggle links 56, 57, -s that the toggle linkages maintain themselves in position: and by reason of the engagement of the toggle links 54, with the slider 48, the parts are held firmly in position and subljected to little or no wear. It is preferred `in many ways within the scope oft e appended claims.

lWhat I claim as new and desire to secure by Letters Patent is: vi 1. In a device of switch having fixed and movable contacts, rst and second toggle'linkages, means to produce spring effects upon the toggle linkages to move the same into and hold the same in end positions, said second toggle linkage being connected to the movable contacts to hold the same in openand closed positions, and means connecting said first and second toggle linkages whereby the said first linkage may move the said second linkage between end positions, said first toggle linkage having lost motion with respect to said second toggle linkage.:

2. In a device as set forth in claim 1, a pair of independent pivoted lever arms, each the class described, a

of said arms establishing an end pivotal point for av corresponding toggle linkage, and a single spring operating upon both said lever arms to produce the spring effect upon both said linkages. ,A

3. In a device as set forth in claim 1, the provision of a pair of independent lever arms and spring means to actuate said arms,

one ofsaid lever armsv producing a `spring tamara toggles to establish the spring effect thereon, and a spring to aetuate said toggle arms, a heat insulating skirt surrounding the heating element of said device, said lever arms extendng'outside of said skirt, said spring being located outside of said skirt whereby it is protected against loss of temper by heating from said element. V

5. In a device of the class described, a switch plate, fixed and movable switch contacts, said fixed contacts being supported on but insulated from said plate, said platehaving a slot therein, a slider movable in said slot, a bridge loosely carried by said slider and supporting said movable contacts to guide them into and out of conductive relationship with said fixed contacts, a toggle linkage to hold said slider in end positions in which the circuit is made or broken by said contacts, and thermostatically controlled means to actuate said slider, said means inciuding lost motion devices and ydevices to quickly move said toggle linkage between its end positions following the operation of sa'id lost motion devices. i

6. In a device of the class described, a thermostatically actuated bar, a switch including fixed and movable elements, a first and a second toggle linkage, said second toggle linkage being connected to said movable element-s to hold the saine in circuit opening and circuit closing positions, said first toggle linkage having a lost motion connection with said second toggle linkage and a lost motion connection with said bar, 'whereby the movement of said bar causes after the absorption of said lost motions a quick movement of said second toggle linkage between its end positions.l

7. In a device of the class described, a switch having fixed and movable contacts, a first and a second toggle linkage, means to product spring efi'ects upon said toggle linkages, the effect upon said first toggle linkage being greater than the effect upon said sec-v ond toggle linkage, said second toggle linkage being connected to said movable contacts to hold the same in circuit opening and circuit closing positions, and a lost motion connection'between said first and said second toggle linkages whereby said first toggle linkage may move to a position approximating the dead center position without movement of said second toggle linkage and thereafter will be snapped by its spring effect means to an opposite end position and thereby move said second toggle linkage to the corresponding end position.

8. In a device of the class described, a frame, a thermostatically actuated bar rigidly connected at one end to said frame, a pair of toggle links having a pivotal connection at their adjacent ends, switch means operated by the movement of said adjacent ends, said bar operating upon said links to move them toward one end position when thebar is heated and toward the other end position Vtion of the cam, whereby to predetermine Vthe temperature at which the toggle links are brought to the dead point by said bar upon movement of the latter.

9 In a device of the class described, a block having a cavity therein, a switch plate closing said cavity, a thermostatically actuated bar located in said cavity, a regulating shaft journaled in said block and said plate, an enlarged portion on said shaft forming a retaining means to prevent axial movement of said shaft, said enlarged portion also forming a cam to cooperate with said thermostatically actuated bar to regulate the movement of said bar at predetermined temperatures, and means to hold said clamping block and switch plate together.

l0. In a device of the class described, a switch having fixed and movable contacts, a rst and a second toggle linkage, said second toggle linkageV being connected to said movable contacts and being adapted to move to small distances on either side of its dead center position whereby to hold the movable contacts in open or closed positions with respectto said fixedcontacts, said first tog gle linkage having a lost motion connection to said second toggle linkageso that said first toggle linkage moves a greater distance on either side of its dead center, and means to establish spring effects upon said toggle linkages, the spring effect upon said first toggle linkage being greater than that upon said second toggle linkage, so that said first toggle linkage causes a rapid movement of said second toggle linkage between its end positions. y

11. In a device as set forth in claim 10, the provision of a single spring and lever arms connecting said spring, the lever ratios of said arms producing a greater spring effeet upon said first toggle linkage than upon said second toggle link e.

In testimony whereof, I a x my signature.

LUDWIG REICHOLD. 

